Thomas C J, Surolia A
Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560 012, India.
Biochem Biophys Res Commun. 2000 Feb 16;268(2):262-7. doi: 10.1006/bbrc.2000.2110.
Recognition of cell surface carbohydrate moieties by lectins plays a vital role in many a biological process. Fucosyated residues are often implicated as key recognition markers in many cellular processes. In particular, the aspects of molecular recognition of fucose by fucose-bindinglectins UEA 1 and LTA pose a special case because no crystal structure of these lectins is available. The study was conducted to elucidate the process of recognition of l-fucose by UEA1 and LTA by correlating structure-based sequence alignment and other available biochemical/biophysical data. The study points out that the mode of recognition of l-fucose is coordinated by the invariant triad of residues the asparagine 137, glycine 105, and aspartate 87. The major hydrophobic stacking residue in this case is the tyrosine 220. The study also reiterates the key role of the conserved triad of residues in the combining site which is a common feature for all legume lectins whose crystal structures are known.
凝集素对细胞表面碳水化合物部分的识别在许多生物过程中起着至关重要的作用。岩藻糖基化残基在许多细胞过程中常被认为是关键的识别标记。特别是，岩藻糖结合凝集素UEA 1和LTA对岩藻糖的分子识别方面存在一个特殊情况，因为这些凝集素没有晶体结构。该研究通过基于结构的序列比对以及其他可用的生化/生物物理数据，来阐明UEA1和LTA对L-岩藻糖的识别过程。研究指出，L-岩藻糖的识别模式由天冬酰胺137、甘氨酸105和天冬氨酸87这一不变的三联体残基协调。在这种情况下，主要的疏水堆积残基是酪氨酸220。该研究还重申了结合位点中保守三联体残基的关键作用，这是所有已知晶体结构的豆科凝集素的共同特征。
